In Search for Higgs Boson, UB Physicists Have Played a Role

BUFFALO, N.Y. -- University at Buffalo physicists are among researchers engaged in one of modern history's most exciting scientific endeavors: The hunt for the elusive Higgs boson, a subatomic particle that could help explain why objects have mass.

The particle is the last particle in the Standard Model of particle physics that scientists have yet to observe conclusively. If discovered, the Higgs boson would help validate the model, which describes how particles and forces interact with one another. The model enables physicists to describe how the world around us works.

On Wednesday, CERN, the European Organization for Nuclear Research, announced that research teams working with the Large Hadron Collider (LHC), the world's strongest particle accelerator, had observed a particle with properties consistent with the Higgs boson (See http://public.web.cern.ch/public/.

"After more than 20 years of involvement in this worldwide collaboration, we are witnessing the first, truly outstanding physics result related to the Higgs particle," said Avto Kharchilava, an associate professor of physics at UB and long-time LHC team member. "I am really proud to be a part of the race -- no matter that it takes decades."

Kharchilava and department colleague Ia Iashvili are among scientists who planned and built the Large Hadron Collider's Compact Muon Solenoid detector (CMS), which researchers are using in the search for the Higgs. Experiments with the CMS are one of two general-purpose LHC experiments that are capable of searching for the Higgs particle, Kharchilava said.

Today, Kharchilava is a member of the Higgs Publication Committee Board that oversees the final steps and scrutiny that the CMS collaboration must undertake before results on Higgs particle searches are made public.

Iashvili, also an associate professor, is one of two scientists in charge of jet energy scale calibration, a process that is critical to the CMS project's ability to identify the Higgs boson, should it appear. Salvatore Rappoccio, an assistant professor who will be joining UB from Johns Hopkins University this August, is also a part of the calibration team.

Rappoccio explained the nature of the work: "The production and decay of the Higgs boson often involves particles called 'quarks,' which ordinarily make up protons and neutrons in everyday matter. However, since these quarks cannot exist alone, they are not detected directly. Instead, they create sprays of stable particles called jets, which are observed in the CMS detector. We are working with a large team of scientists at the CMS experiment in measuring these jets to estimate the energy of the quarks involved in the Higgs decay."

Besides Rappoccio, Iashvili and Kharchilava, UB physicists have been involved in many aspects of the Large Hadron Collider experiments, from running the CMS detector to predicting how particles should look when they appear.

Theoretical physicists at UB who have contributed to LHC projects include Associate Professor Doreen Wackeroth, Assistant Professor Dejan Stojkovic and Professor Richard Gonsalves.

"The search for the Higgs boson at the LHC is one of the most impressive scientific endeavors of our time," said Wackeroth, who has been working on Higgs physics since 1992. "The existence of a Higgs boson was proposed by a number of theorists in 1964. Since then, physicists have been searching for this particle at high-energy accelerator experiments, but until now, it has always escaped detection."

Like her colleagues, Wackeroth expressed excitement about CERN's Wednesday announcement: "They have discovered a new boson!" she said. "It is consistent with a Higgs boson. We do not know yet if it is the one predicted by the Standard Model -- this will be decided with more data. This is just the beginning of an exciting new era in particle physics. Everyone feels that this is an historic milestone."

Besides faculty members, a number of UB students and postdoctoral researchers are working on LHC projects.

Related Stories:

UB Physicists Celebrate LHC Startup, Decade After Its Inception: http://www.buffalo.edu/news/9627

CERN Announcement of Particle Consistent With Higgs Boson: http://press.web.cern.ch/press/PressReleases/Releases2012/PR17.12E.html